Traditional technologies and designs for airfoil air flow design and lift are well known in aeronautical industries, particularly applied in the implementation of wing structures for airplanes and other vehicles, propellers and for ground-effect vehicles. Jet and propeller propulsion and traditional wing technologies, relating to commercial and private airplanes, military and space applications, have historically dominated the aeronautical industries and markets in traditional airfoil design for air travel, transport and combat. Ground-effects type vehicles, such as amphibious air driven technologies and hover craft, as well as vertical take-off and landing vehicles, may have had historically limited development and success due to the previous complexity of traditional aeronautical theory and its potential inaccuracies.
A conventional and traditionally accepted basis for flight is the acceptance that the preferred means to create lift for an airplane is to utilize conventional airfoil designs based upon presumptions from Bernoulli's principle for evaluating air flow. This basis for flight and airfoil design has been characterized by some as the “Aeronautical Engineering Blunders of the 20th Century”. Some have developed a critique of the traditional basis for flight and airfoil design as exemplified and described on the website http://www.aeronautics.ws (found at www.aeronautics.com April 2008) (Gent, G.), the disclosure of which is hereby expressly incorporated by reference. It has also been propositioned that the use of more fundamental principles of physics, such as Newton's Laws of Motion, better define aeronautic principles for flight development, and specifically, airfoil air flow design and lift.
It is with the traditional design of airfoils for aircraft and how the airfoil is traditionally incorporated for flight that commonly known problems associated with traditional aircraft are raised. One such identified problem is the common misunderstanding of how an airfoil produces lift. One such popular but misguided theory of airfoil flow may be the principle of equal transit time of flow above and below wing. The principle may assume that flow over the curved upper portion of a traditional wing occurs in the same time as flow over a more flat lower portion of the wing. Utilizing Bernoulli's law, the greater velocity above the wing would require the upper surface pressure to be less than the lower surface pressure, and hence lift.
One traditional theory that may be advanced by aerodynamic teaching, and in light of the above-described theory, is that actual differences in velocity between above-wing and below-wing air flows may be attributable to “circulation”, turbulent air flows caused by pressure differentials, rather than air flows having equal transit time above and below wing with a potentially more preferred laminar flow. This theory may be conceptualized as circulatory movement or flow is superimposed on passing flow, such that the flow over an airfoil is considered flow with circulation. It may then be determined that the rate of interception of circulation in upward momentum, plus the rate of production of downward momentum in recurvature of flow downward, may be considered to equal net lift. Furthermore, induced drag may be a factor wherein rearward thrust of circulation may be greater than forward thrust. Other circulation flows and drag may be considered in traditional attempts to optimize lift and thrust for airfoils embodied as fixed wings of an aircraft. In respect to this traditional theory, losses in lift may be due in part to upward circulation around the wing ends. This loss which may be considered “lateral loss” in some theories reduces upward momentum and relieves pressure differentials that are required for lift.
Under these and other traditional theories the identified need is to reduce factors that ultimately reduce net lift or efficiency of the wing. Recognized and yet heretofore inadequately addressed needs for achieving more adequate lift may have been previously understood as addressed by: increased wing area, increased flow velocity, and increased coefficient of lift.
Some studies have found, however, that the airfoil commonly referred to as an accelerating or acceleration airfoil outperforms conventional airfoils by an increase in flow velocities and pressure differentials for lift. The accelerating airfoil studied in the Gent reference incorporated in this disclosure and cited above found a greater angle of attack in combination with airfoil shape produced limited drag with preferred lift over drag factors. The curving profile along the bottom of the airfoil in the Gent reference appears to be developed for the airfoil tested such that the distance top and bottom from the stagnation point of the leading edge to the trailing edge was the same. In so developing an accelerating airfoil, equal negative pressures were recorded at all angles of attack, top and bottom, creating lift when under traditional Bernoulli-type theories no lift should have been generated.
In the continuing efforts to better understand the benefits of accelerating airfoils, the ongoing desire is to reduce drag and other factors that reduce lift by presenting high velocity air and delivering the air to a preferred design of airfoil to generate the lift. Accordingly, the thought is that the combination of air speed and lift factor results in the actual lift. Heretofore, these concepts have been addressed primarily by single wing aircraft.
However, in one fan-based technology, as found in U.S. Pat. No. 6,261,051 issued to Kolacny, hereby expressly incorporated by reference, a tangential fan and duct are disclosed utilizing fan blades creating a preferred internal ratio of the fan and configured having preferred inner surface curvatures of fan blade airfoils. The technology addresses preferred low and high pressure zones within the tangential fan and the duct as well as preferred laminar flow through the system. The fan blades are configured preferentially to allow for maximized flow with respect to the fan, intake duct and exhaust flow and to improve upon the relationship between the exhaust flow velocity and fan blade tip speed, wherein the fan blade tip speed may be minimized for the greatest amount of exhaust flow velocity.
The '051 patent technology might be thought to be a development of alternative air flow generation independent of traditional technologies that provided assisted air flow. On the other hand, other technologies providing air flow, and propulsion generally, are typically found in common jet engine systems. However, in order to achieve thrust and lift in traditional aircraft, jet engines are typically utilized in order to create a velocity difference between the air entering the ram jet body and the air exiting the system. The air flow may be introduced by traditional axial fans, such as in a turbine jet. The velocity difference between the entrance and exit air is traditionally accomplished by the addition of heat to that portion of the airstream flowing through the ram jet body. Burning liquid fuel inside the ram jet body is one known method of adding heat to a ducted airstream.
Other aircraft have been developed that had taken then untraditional approaches to accomplishing preferred lift with traditional jet engine technology. In some circumstances, the additional complexity was to design an aircraft that could generate on its own enough initial lift to allow the aircraft to take off at a non-moving initial position and even to provide some aspects of hovering while in flight or from the take off. One such aircraft is commonly referred to as the Harrier Jet.
A simplified explanation of the Harrier design is that two jet engines are configured on each side of the air craft and each incorporate an adjustable port to direct thrust of each engine downward to achieve lift for standing take off or to hover. This technology has been pursued initially by British military and other military interests generally for military aircraft application.
The Harrier Jet technology is relatively expensive and may be difficult to maintain, while another primary deterrent is the apparent lack of precise control desirable for certain applications, such as preferred three-dimensional flight control and low or even no flight speed control. In one example, a potential downside is the lack of provision for a stall or loss of power in which the pilot would have very little option in attempting to land the plane without power to provide thrust and lift for a safe landing. Furthermore, the Harrier design may not take advantage of more preferable airfoil designs and configurations that would result in greater lift and thrust, in take off, flight, and landing, particularly as a winged and jet engine driven aircraft. Additionally the Harrier Jet design incorporates technology and resultant thrust effects that may be undesirable with respect to the location of takeoff and landing of the jet, such as over surfaces that are detrimentally affected by the weight of the aircraft generally and the downward thrust of secondary jet engines to achieve lift.
A second and previously developed alternative design is the Osprey design, a design considered by some to be a medium-lift, tilt-rotor aircraft developed by Boeing and Bell Helicopters. A simplified explanation of the Osprey design is that two tilt-rotors on each wing are configured to provide lift, as may be comparable to a helicopter, when taking off or landing vertically. The rotators or nacelles rotate 90 degrees forward once airborne, converting the aircraft into a turboprop aircraft. The technology is relatively expensive, while another primary deterrent is the apparent lack of precise control desirable for certain applications, such as preferred three-dimensional flight control and low or even no flight speed control. The problems and deterrents may have been reflected in the number of setbacks the military and developers had in producing serviceable aircraft. Again, a further potential downside is the lack of provision for a stall or loss of power in which the pilot would have very little options in attempting to land the plane without power to provide thrust and lift for a safe landing. Furthermore, the Osprey may not take advantage of more preferable airfoil designs and configurations that would result in greater lift and thrust, both in take off, in flight, and in landing, particularly as a winged and propeller driven aircraft.
Other alternative designs have been considered for vehicles generally, incorporating some aspects of air flow for creating lift of the vehicle from the ground surface based upon the ground effects created by downward-directed airflow. Some of these designs may be considered amphibious in application, and may include the commonly known swamp boat design that generates thrust from the propulsion created by a rearward axially driven fan. Others may have only been conceived in the theoretical or in fictional works in applications for hover vehicles. Craft that have actually been produced in real world application are designs commonly referred to as hover craft and typically lack preferred control over thrust and lift in order to achieve propulsion, much less precise control desirable for certain applications such as preferred three-dimensional flight control and low or even no flight speed control. Some of these designs may not address control over production of thrust in combination with lift in order to propel the vehicle forward or to lift the vehicle from ground surface. Others may address thrust by alternative means similar to the swamp boat by way of an external and fixed rearward axial fan. Some of these previous attempts are disclosed in U.S. Pat. Nos. 3,877,542, 4,747,459, and 3,460.647.
While many of these drawbacks and inadequacies in the prior art are known and documented, no heretofore developed technology has adequately addressed these needs, and the traditional technologies described above do not bridge the gap or fully achieve preferred control over lift and thrust for propulsion, or to do so for standing take off, to hover, and in takeoff, flight, landing and loss of power scenarios for aircraft.
Heretofore those in the industry may not have considered the possibility of other propulsion possibilities, and the provision for control of the generation of combinations of thrust and lift from air flow providing propulsion in order to achieve not only vertical lift for take-off and for flight, but to achieve preferred flight control from air propulsion such as preferred three-dimensional flight control and low or even no flight speed control. Heretofore generating a controlled combination of thrust and lift for precise and controlled flight and landing in the absence of power supplied to the propulsion system has not been adequately addressed or achieved in traditional designs. Furthermore, it may have even been thought as a recognized drawback in aeronautic and ground-effect systems to incorporate the provision for controlled thrust and lift to accommodate not only lift but as also the source for thrust in forward travel or flight. It may have also been heretofore thought that airfoil design could not be achieved that would provide the necessary lift for real world applications of vehicle dimensions and weight, particularly for any airfoil design beyond traditional single wing aircraft. Additionally, recognized needs for the necessary air flow velocity and coefficiency of lift, as well as what might have been thought of as the requirements for larger airfoil area, may have led aeronautics and ground effects industries to other types of propulsion thought as being singularly capable of producing the necessary thrust and lift apart from airfoil design and jet engine propulsion generally. This may be particularly true wherein the incorporation of air propulsion in combination with jet propulsion has only remained in the development stages as evidenced by shortcomings of the Osprey design.
In addition to all of the deficiencies previously described, the prior art may suffer from one or more of the following deficiencies. The prior art may require further and additional thrust and lifting systems and separate and additional power generation for the propulsion system to achieve a desired result, such as in the take-off and flight of traditional aircraft or in the lack of provision for propulsion in the event of power loss during flight. The prior art may not even provide for the combination of control of thrust and lift, such as preferred three-dimensional flight control and low or even no flight speed control, and for the full propulsion of a vehicle such as an aircraft or ground-effects vehicle. The prior art may even lack the preferred understanding of airfoil design and implementation into a propulsion system, potentially only directed to lift by air flow.
The present invention seeks to overcome one or more of these and other deficiencies of the prior art.